package com.example.opengldemo.vertex_shader_more.light_halo;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;

import android.opengl.GLES30;

import com.example.opengldemo.util.ShaderUtil;


public class DrawFlare 
{	
	int mProgram;
    int muMVPMatrixHandle;
    int maPositionHandle;
    int maTexCoorHandle;
    int mColorHandle;
    String mVertexShader;
    String mFragmentShader;
	
	FloatBuffer   mVertexBuffer;
	FloatBuffer   mTexCoorBuffer;
    int vCount=0;   
    float UNIT_SIZE=1.0f;
    
    public DrawFlare(MySurfaceView mv)
    {    	

    	initVertexData();

    	intShader(mv);
    }
    

    public void initVertexData()
    {

        vCount=6;
       
        float vertices[]=new float[]
        {
        	-UNIT_SIZE,UNIT_SIZE,0,
        	-UNIT_SIZE,-UNIT_SIZE,0,
        	UNIT_SIZE,-UNIT_SIZE,0,
        	  
        	UNIT_SIZE,-UNIT_SIZE,0,
        	UNIT_SIZE,UNIT_SIZE,0,
        	-UNIT_SIZE,UNIT_SIZE,0
        };
		


        ByteBuffer vbb = ByteBuffer.allocateDirect(vertices.length*4);
        vbb.order(ByteOrder.nativeOrder());
        mVertexBuffer = vbb.asFloatBuffer();
        mVertexBuffer.put(vertices);
        mVertexBuffer.position(0);



        

        float texCoor[]=new float[]
        {
        		1,0, 1,1, 0,1,
        		0,1, 0,0, 1,0        		
        };        

        ByteBuffer cbb = ByteBuffer.allocateDirect(texCoor.length*4);
        cbb.order(ByteOrder.nativeOrder());
        mTexCoorBuffer = cbb.asFloatBuffer();
        mTexCoorBuffer.put(texCoor);
        mTexCoorBuffer.position(0);




    }


    public void intShader(MySurfaceView mv)
    {

        mVertexShader=ShaderUtil.loadFromAssetsFile("z_real_light/light_halo_vertex.sh", mv.getResources());

        mFragmentShader=ShaderUtil.loadFromAssetsFile("z_real_light/light_halo_frag.sh", mv.getResources());

        mProgram = ShaderUtil.createProgram(mVertexShader, mFragmentShader);

        maPositionHandle = GLES30.glGetAttribLocation(mProgram, "aPosition");

        maTexCoorHandle= GLES30.glGetAttribLocation(mProgram, "aTexCoor");

        muMVPMatrixHandle = GLES30.glGetUniformLocation(mProgram, "uMVPMatrix");  
        
        mColorHandle=GLES30.glGetUniformLocation(mProgram, "color");
    }
    
    public void drawSelf(int texId,float[] color)
    {        

    	 GLES30.glUseProgram(mProgram); 

         GLES30.glUniformMatrix4fv(muMVPMatrixHandle, 1, false, MatrixState.getFinalMatrix(), 0); 
         
         GLES30.glUniform4f(mColorHandle,color[0],color[1],color[2],color[3]); 

         GLES30.glVertexAttribPointer  
         (
         		maPositionHandle,   
         		3, 
         		GLES30.GL_FLOAT, 
         		false,
                3*4,   
                mVertexBuffer
         );       

         GLES30.glVertexAttribPointer  
         (
        		maTexCoorHandle, 
         		2, 
         		GLES30.GL_FLOAT, 
         		false,
                2*4,   
                mTexCoorBuffer
         );   

         GLES30.glEnableVertexAttribArray(maPositionHandle);  
         GLES30.glEnableVertexAttribArray(maTexCoorHandle);  
         

         GLES30.glActiveTexture(GLES30.GL_TEXTURE0);
         GLES30.glBindTexture(GLES30.GL_TEXTURE_2D, texId);
         

         GLES30.glDrawArrays(GLES30.GL_TRIANGLES, 0, vCount); 
    }
}
